Page 19 of Daikon

The panel at last sprang free and clattered to the floor, sending Yagi jumping back with a curse.

“This doesn’t look like a bomb,” he observed, sucking blood from his nicked finger as he peered into the cavity he had exposed.

It was packed with electrical equipment, wires, and connectors.

The cavity on the other side was found to be identical after the second panel was removed.

The largest components were four identical black boxes that encircled the girth of the object.

Each was stamped with a unique code, a combination of letters and numbers, and bore several labels in English, the largest one impressed on a metal plate riveted to the box.

Yagi pointed to it as Kan took a photo of the interior space.

“What does that say?”

“?‘Warning: High Voltage,’?” Kan translated. “?‘Disconnect power before removing cover.’?”

“High voltage.” Yagi’s eyes followed the cables that ran from each of the black boxes to a smaller white unit positioned at the end. “Those must be batteries, then.”

Kan examined the black boxes more closely.

There were two terminals on each, one marked “Transmitter Antenna,” the other “Receiver Antenna.” An eight-pin electrical plug labeled “To Control Box” was situated in the center.

Was this some sort of recorder? Perhaps.

But recording what? It could also be an electronic triggering apparatus. But why would there be four of them?

He took another photo, close up.

They paused to refresh themselves from the bucket of water, standing at the open door to catch whatever breeze was wafting in off the sea.

After two hours of work, Nakamura and Wada were no longer stiff in Kan’s presence.

They casually loitered. A streak of white appeared in a break in the clouds overhead.

“B-29,” said Nakamura, taking another drink. It was the second time they had seen a high-altitude condensation trail that morning, a single line pointing northeast.

They returned to work. As the navy men sawed at and pried off the rest of the casing, Kan undertook a more detailed examination of what had been exposed.

He was struck by something that had escaped his notice before: fingerprints.

Greasy smudges and black smears on interior surfaces, a few bearing the distinct impression of ridges.

Seeing them, he imagined American scientists, engineers, builders, bending over this very space just like he was now doing, sweating in the heat as he was now sweating, their hands sore and nicked and dirty, stained with oil and lubricant, leaving fingerprints just like his.

The sense of their presence, for a fleeting moment, was eerily strong.

Had one of them been Stanley J. Rothstein?

He noticed something else as well: The interior had a makeshift quality about it, evidence that the builders had made adjustments as they worked.

There were bolt holes that had been redrilled where two surfaces had not lined up.

And there—the corner of that bracket had been filed down to fit into that tight space.

And were those hammer marks on the edge of that flange?

In outward appearance this object bore no resemblance to the separator Kan had built at the Riken.

But in these small evidences, he recognized the same experimental nature of his own work.

This thing, this device—it had not come from a factory.

It had been painstakingly assembled by hand.

By midafternoon the outer casing had been completely stripped off and the interior space emptied of its complex components.

What remained of the object, its essential core, was a thick cylinder—the tube that had run through the entire length—connected to the heavy nose component machined from solid steel.

It looked like a gigantic club, a two-meter-long handle with a monstrous bulb on the end.

Kan, nearing the end of his second precious roll of film, photographed it from both sides.

Before proceeding further, he probed the tube with the pole he had used the previous evening and marked the location of the obstruction on the outside with chalk.

He ran the wand of the Geiger-Müller counter over the spot.

It gave only a slightly elevated reading.

If the obstruction was a strong radiation emitter, the two-centimeter-thick walls of the steel tube were absorbing most of the rays.

“What are you doing?” asked Seaman Nakamura. He and Seaman Wada were watching over his shoulder.

Kan smiled and shook his head. “I don’t really know.”

The two young men hurriedly stepped back as Yagi returned. He was carrying a galvanized iron water pipe, somewhat rusty. He stood it on end. It extended more than a meter over their heads.

“That will do nicely,” Keizo Kan said.

He eased the rod into the front of the tube, the end attached to a wooden block to keep it elevated to center. He fed it down, down, more than two meters down until it encountered the obstruction.

“Be very careful,” he instructed Yagi. “Just gently to start.”

Yagi, using a heavy hammer, delivered a tentative tap onto the end of the pipe. The modest release of energy passed down its length into the obstruction and did not move it at all.

He struck the pipe again, and again, progressively harder, the clang of metal on metal making Kan and Nakamura and Wada all blink together.

Still no movement.

Yagi cast the hammer aside in disgust. He went to the corner, rummaged through the larger tools, and returned with a sledgehammer, a determined look on his face.

“Let’s see how it likes this,” he said.

He began cautiously, gripping the sledgehammer close to the neck. Still nothing. He shifted his grip downward and started swinging from farther back, until Kan was wincing and shying away.

“Nakamura,” Yagi barked. “Take over.”

Kan relinquished his steadying hold on the pipe to Nakamura and stepped back, rubbing his hands. Nakamura repositioned the pipe. Yagi brought the sledgehammer farther back.

A metallic clang.

Another. Another. Whatever was stuck in the tube remained tightly wedged.

“Come on, you bastard,” Yagi murmured.

Nakamura pulled the pipe back, gave it a twist, and repositioned it up against the obstruction. Yagi took a fresh grip on the sledgehammer, lined it up, made a few trial movements, then brought it back, all the way back, and struck a resounding blow.

“It moved,” he said.

Two more blows and the obstruction broke free. With a series of taps Yagi drove it back down the tube to the rear end, where Wada stood ready to catch it. Wada braced himself, feet apart, cradling his hands underneath the object as it appeared.

It was too heavy for him. It fell to the floor.

It was a metallic plug—it was hard not to think of it as a projectile—the width of Kan’s outstretched hand and the length of his forearm from the fingertips to the elbow.

His first reaction as he gazed down at it was relief, for it appeared to be a cylinder of copper, not another uranium mass.

But then he realized that what he was seeing was only a thin exterior sheathing, a series of bands, presumably intended to hold the interior elements together and ensure a snug fit inside the tube.

He took two photographs from different angles. Then Yagi, at Kan’s direction, went to work at the copper sheathing with a screwdriver and pliers, prying it up and peeling it off as the scientist and the two seamen watched over his shoulder.

Released from the encasing bands, the plug—the projectile—fell apart on the floor.

“There you go,” said Yagi. “Uranium. It looks just the same.”

There were nine rings of the metal, the same plum patina as the rings retrieved from the front of the tube, coated on the inside with the same silvery plating. Behind them was a tungsten carbide plug identical to the sleeve of the material in front, the same green flecks. And behind that: steel.

Yagi stood up with a grunt and stretched until his back cracked. Keizo Kan, lost in thought, took no notice. He was turning the rings over in his hands, examining them, assessing them, adding them to the basic design that was coming into focus.

They varied in thickness like the uranium rings in the nose—again, individually cast—but were thinner and substantially larger, large enough to fill the whole tube.

Individually, they seemed to weigh about four kilos, making the entire stack of nine rings heavier than the forward uranium assembly—at least thirty-five kilos in total, perhaps as much as forty.

And the thin silver plating, it was on the inner surface of each ring, not on the outside as with the rings in the nose.

Kan fetched his wooden case.

The Geiger-Müller counter produced the same vigorous reading as the forward uranium mass, more than 200,000 counts per minute, when he held the wand over the scattered rings.

He stacked them together, one on top of the other, returning them to their original configuration, and inserted the wand into the hole in the center.

The click rate soared in intensity, an angry buzz, the needle on the counter leaping to the top of the scale.

Kan yanked the wand out and kicked the stacked rings over, scattering them across the floor.

The three navy men eyed him curiously. Yagi said, “What did that mean?”

Kan didn’t answer. The workshop had receded as the bomb—for it was a bomb—filled his mind.

The ten-centimeter hole in these rings—it matched the width of the uranium rings in the nose.

When the projectile was fired down the gun barrel, this rear stack of rings would not smash into the ones in the nose, it would slide onto them, hastening and controlling assembly into one solid mass.

Assembled, the silvery inner plating on the rear rings would come into contact with the plating on the exterior of the forward rings, now nestled inside.

What was the purpose of that? And what were these four small nubs, no bigger than the end of his little finger, that were attached to the outermost ring?

Yagi and Nakamura went to the water pail at the open door of the workshop for a drink. Seaman Wada remained where he was, gazing at the uranium rings on the floor. He picked one of them up. The thickest and heaviest one. He hefted it, marveling at the weight.

Kan didn’t notice. He was imagining a theoretical nuclear chain reaction, how it would begin. The silvery plating… was it some sort of initiator? A substance that would create a burst of neutrons when the two masses of uranium came together?

Wada, uranium ring in hand, began wandering toward the back of the workshop.

Kan didn’t notice. The ring configuration of the uranium filled his mind.

Why rings? Because it facilitated the mating of projectile and target upon firing.

But there was more. It also allowed for a larger mass of enriched uranium to be assembled and maintained in a subcritical state, for a ring presented far more surface area than a solid slug—surface area from which neutrons could escape.

If this mass of uranium had been cast as a solid projectile or with only a small hole in the center like the rings in the nose, the surface area would have been greatly reduced and—

He glanced up. Cold washed over his body. Wada was bending over the stack of uranium rings from the nose that Kan had placed out of harm’s way in the corner. He was comparing them, noting how the larger ring in his hand appeared to be exactly the right size to fit onto the stack.

The scientist opened his mouth to shout a warning just as a blue flash engulfed the garage and a wave of warmth struck him.

A crackling sensation passed through his body and the Geiger-Müller counter let out a shriek.

Wada reeled back, the ring flying from his hand.

The blue light vanished. The Geiger-Müller counter subsided.

The young seaman, recovering from his initial shock, looked over at Kan in dismay. “Pardon me! I’m sorry! I’m sorry!” He repeatedly bowed, then began rubbing his hand.

Kan stood frozen, his eyes locked on the uranium rings on the floor beside him. He became aware of a metallic taste in his mouth, like tinfoil on a piece of chewing gum touching a filling. And a sharp, chlorine-like smell. Ozone.

Click… click… click. The Geiger-Müller counter was reading only background radiation. The workshop was very still. Outside, cicadas were buzzing.

“Bakayaro!” Yagi strode over from the water pail and gave Wada a clout in the head. It seemed the proper thing to do, even though he did not know what the young seaman had done.

“Outside,” Kan said. “All of you. Go outside.”

Yagi, spitting curses, shoved Wada and Nakamura through the door.

Left alone, Kan continued to stand very still, as if any sudden movement might reawaken the beast. Finally he forced himself to take a small step.

The uranium did nothing. The unimaginably ferocious power of fission had apparently retreated back inside the rings.

He bent down and touched the ring Wada had dropped. It was burning hot.

He approached the nose assembly and held his hand close to the stacked uranium rings. Heat was radiating off them as well. He pulled his hand away and stepped back.

There was no longer any doubt.

“Genshi bakudan,” he whispered.

Atomic bomb.